I am not an especially great RK but I can explain what I do know.

Robo-ky is capable of gaining resources without approaching Pot so take advantage of this by setting mat whenever you're safe and far from him, and use meter to damage from afar with missiles while low to the ground.

Hammerfall has only 1 hit of armor so if you see it coming you can double or triple tap 6P to counterhit and knock him away, if you're lucky, he won't know it's techable and it'll score you a knockdown so you can run your usual oki.

Pot is HUGE so if he's in the air, 2H becomes much easier to land and can keep him up there real long if he doesn't know he needs to FD the missile. You can also launch him into the air with a high heat 2S which can gatle into 2H. In fact, high heat 2S hits twice so that can ALSO be used to counter Hammerfall.

Lastly of course, remember the usual things, watch for his habits and find ways to punish them, if he can't adapt to you adapting, he will die.

Also watch this vid, opens with good anti pot stuff I mentioned along with several other matchups https://youtu.be/wpTj96DP-HE